Centralized traffic controlling system for railroads



W. D. HAILES April 4, '1939.

CENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed Jan. 30, 1957owe o m Lamru 9 35 23 W Patented Apr. 4, 1939 UNITED STATES CENTRALIZEDTRAFFIC CONTROLLING SYSTEM FOR RAILROADS William D. Hailes, Brighton, N.Y., assignor to General Railway Signal Company, Rochester,

Application January 30, 1937, Serial No. 123,167

Claims.

My invention relates to remote control systems of the type comprising acontrol ofiice and a plurality of field stations connected by a linecircuit over which codes are transmitted for the 5 purpose ofcommunicating intelligence between the several stations and the office.

In systems of the type described, it is customary to carry the linecircuit through the several stations in series and it follows that, inorder to control a particular signal at any one of the stations, it isnecessary to first transmit a station selecting code over the linecircuit for selecting the desired station and then transmit a code forcontrolling the desired signal in the desired manner.

My invention provides a means for deliberately opening the line circuitto put a signal to stop with greater assurance than by sending a regularstop code for this purpose.

My invention also provides means whereby an open line circuit condition,due to a faulty condition of the line circuit, puts all signals to stopat those stations connected to the line circuit and having the specialorganization provided by my invention, as shown in the accompanyingdraw- In one form of remote control system which has been proposed, thecommunication between the ofiice and the several stations isaccomplished by means of codes which are formed by periodicallyinterrupting the normally closed line circuit. In practicing myinvention, I provide at each station a fault relay arranged to beoperated in a distinctive manner if the line circuit is open fora timeinterval longer than the greatest period of open circuit normallyoccurring during code transmission. The fault relay is a slow releasingrelay in series with the line circuit at the field station and is sodesigned that it will release when the line circuit is held open for anextremely long period of time.

The slow acting fault relay remains in its energized position, in whichposition it completes a stick circuit for a fault stick relay, thislatter relay controlling the signal clearing circuits at the associatedstation.

I will describe a preferred form embodying my invention and will thenpoint out the novel features thereof in the appended claims.

The accompanying drawing is a diagrammatic view illustrating one form ofremote control system embodying my invention. I have shown a remotecontrol system comprising a control office and a single field stationconnected by a twowire line circuit and although only one station isillustrated, it will be understood that additional stations areordinarily provided and controlled in series over the illustrated linecircuit.

The line circuit is normally energized and includes a source of currentin the control ofiice, illustrated as being a battery B, and a plurality5 of line relays, one located at the omce and one at each station andall connected in series in the line circuit. Each line relay isdesignated by the reference character F with an exponent correspondingto the location. Relay F is located 10 in the control oflilce and relayF is assumed to be 7 located at the first field station.

A transmitter relay is also provided in the control oflice and at eachfield station, designated by the reference character PL with anappropriate 15 exponent and equipped with back contacts included in theline circuit. The transmitter relays may be selectively operated bymeans forming no part of the present disclosure, to interrupt the linecircuit for operating step-by-step mecha- 20 nisms at all locations insynchronism. The stepby-step mechanisms are operated in response to theimpulses applied to the line circuit by virtue of the operation of theline relays.

A code selecting relay CS is provided in the 25 control oifice forselecting the polarity with which the line circuit is energized duringeach impulse period, this polarity being selectively applied to the linecircuit through contacts I and 4 of relay CS. Since the line circuit isnormally energized by energy applied from battery B, with the terminalof this battery connected to the lower line, the line relays are assumedto have their polar contacts normally positioned to the left. When relayCS is picked up, current is re- 35 versed in the line circuit and theline relays operate their polar contacts to the right. For controllingthe various local circuits in the control office and at the fieldstations, line repeater relays are ordinarily provided, such as relay PF40 shown as being energized when relay F has either of its contacts 5 orl9 closed. 7

One form of remote control system operating in the manner thus fardescribed is disclosed and claimed in an application for Letters Patentof 45 the United States, Ser. No. 635,062, filed by T. J. Judge, onSeptember 2'7, 1932, corresponding to British patent 419,401, forCentralizedtraffic con-' trolling systems. Systems of this character areparticularly suitable for, though in no way limited to, use incentralized traffic controlling systems for railroads, in whichgoverning devices such'as railway switches and signals located ad-'jacent the several field stations, are controlled from a control ofliceand in which the condition v application Ser. No. 635,062.

of the apparatus at the several stations is indicated in the controlofiice.

In order to provide a means for quickly putting signals to stop at allstations equipped with the fault relay and associated circuits, Iprovide a key K in the control oifice for opening the line without thenecessity of applying codes thereto.

Fault relay FL at the field station is connected across diagonal pointsof a network comprising rectifiers 8|, 82, 81 and 88, such rectifiersbeing included in the line circuit for the purpose of causing current toalways flow through the winding of relay FL in the same direction,irrespective of the polarity of the impulse current applied to the linein the control office. This is necessary to prevent the momentaryrelease of relay FL, even though this relay is slow releasing, when thecurrent through its winding is reversed, which would momentarily breakthe stick circuit for the fault stick relay FLS.

Each station is assumed to be provided with left and right directionrelays LD and RD respectively and signal control relays IAG, ZAG, IBGand ZBG for controlling signals IA, 2A, IB and 23 respectively. Stationrelay STA at the associated station is picked up when this station isselected from the control office. One form of system comprising suchdirection and signal control circuits is disclosed and claimed inLetters Patent of the United States, issued to T. J. Judge, No.2,045,951,

issued June 30, 1936. Reference may be made to this patent for thedetailed operation of the station relay STA, the direction relays LD andRD and the signal control relays, all of which have been given referencecharacters corresponding to the associated relays of the Judge patent.

Furthermore, the reference characters associated with the contacts ofrelays STA, LD, RD and the signal controlling relays are the same asillustrated in connection with the corresponding contacts of thecorresponding relays of Patent 2,045,- 961. Likewise referencecharacters I, 3, 4, 5, l9 and I02 of the line circuit organization inthe accompanying drawing correspond to similar reference characters inthe above mentioned Judge The reference characters used in connectionwith the apparatus added in accordance with the present invention are inthe series.

During the normal-at-rest condition of the systern, theback contacts ofrelays PL, PL (and the like) remain closed so that the line circuit isnormally energized. The energization of the line circuit effects theenergization of the line relays and fault relay FL over a circuit whichmay be traced from the terminal of battery B, back contact I of relayCS, normally closed contact 80 of key K, lower line conductor, rectifier8| winding of relay FL, rectifier 82, winding of relay F back contactI02 of relay PL upper line conductor, normally closed contact 83 of keyK, back contact 3 of relay PL, winding of relay F and back contact 4 ofrelay CS, to the terminal of. battery B. Relay FL being energized closesa stick circuit for relay FLS extending from front contact 84 of relayFL, front contact 85 of relayFLS and upper winding of relay FLS, toFront contact 86 of relay FLS is closed for applying potential by Way ofthe contacts of the-LD and RD relays and the contacts of the lic'and RCrelays to the signal control relays, so that the signal control relayscan be selectively controlled inaccordance with the energization 75..

ofthe direction relays, these latter relays being selected and energizedin response to a signal clearing code.

During the operation of the system for the transmission of codes, theline circuit is opened at such a rate that relay FL does not release andtherefore the stick circuit for relay FLS is maintained complete. Whenthe current is reversed in the line circuit from that above described,relay FL is energized in the same direction as previously described byWay of rectifiers 8'! and 88. If a break occurs in the line circuit theline relays and line repeater relays will be deenergized, with linerepeater relay FP in the control ofi'ice closing a circuit at backcontact 89 for lighting lamp L, the steady illumination of this lampbeing an indication to the attendant that the line is in an open circuitcondition. It will be apparent that the intermittent operation of relayFP during the normal impulsing of the system will cause lamp L to flash,thus giving a distinctive indication as to the condition of the line.

The break in the line circuit also effects the continued deenergizationof relay FL and after a period of time determined by the slow actingcharacteristics of this relay, its front contact 84 is opened whichopens the stick circuit for relay FLS, causing this latter relay torelease and at open front contact 86 the circuits of all AG relays aredeenergized, so that they will all be in their dropped away conditionfor putting all associated signals to stop.

It will be also understood that relays FL and FLS are released if theattendant in the control oifice holds key K in its open circuitcondition for an appreciable length of time.

After having thus put the signals to stop, the line wires may be closedup, either by the restoration of key K or, if a. break in the line hasoccurred, by this break being repaired, which will permit the system togo into its normal condition in response to a comparatively longenergization of the line circuit. At the station or stations havingfault stick relays however, the signal clearing circuits are not putinto operation until the fault stick relays are picked up. Thepicking upof these relays may be accomplished by manual means at the associatedstations or, as illustrated in the accompanying drawing, they may bepicked up in response to a signal clearing code.

Assuming that relay FLS is deenergized and that the line is in conditionfor normal operation, the illustrated station is selected and relay STAis picked up in response to the station selection code. Then some signalclearing code is transmitted which energizes either the lower winding ofrelay LD by way of back contact 59 or the lower Winding of relay RD byway of back contact 52, either circuit extending through the lowerwinding of relay FLS and front contact 35, to Relay FLS is thereforemomentarily energized by Way of its lower winding in response to asignal clearing code and its stick circuit again completed, with energyapplied to the signal control relays by way of its front contact 85.

It will be understood that, in the application of this auxiliary controlto multiple field stations, it is not necessary to equip each fieldstation with the control but it might be found desirable to equip onlycertain locations, so that the opening ofthe control line is eflectiveto put signals to stop only at certain desired stations, while thesignals at other non-equipped stations remain in their clear positions,thus not interferring with train operation at those stations not soequipped.

Having thus described a remote control system as one embodiment of thepresent invention, it is desired to be understood that this form isselected to facilitate in the disclosure of the invention rather than tolimit the number of forms which it may assume, and it is to be furtherunderstood that various modifications, adaptations and alterations maybe applied to the specific form shown to meet the requirements ofpractice, Without in any manner departing from the spirit or scope ofthe present invention except as limited by the appended claims.

What I claim is:

1. A centralized traflic controlling system for railroads comprising acontrol office and a field station connected by a normally energizedline circuit; a signal at said station; a slow acting fault relayincluded in said line circuit at said station; a stick" relay at saidstation having a stick circuit energized through front contacts of saidfault and said stick relays, whereby said stick circuit is deenergizedin response to an open condition of said line circuit sufficiently longto drop said fault relay; means independent of said stick circuit forenergizing and picking up said stick relay; and circuit means requiringthat said stick relay be inits picked up position for permitting theclearing of said signal.

2. A centralized traffic controlling systemfor railroads comprising acontrol office and a field station connected by a normally energizedline circuit; a plurality of signals at said station; a slow actingfault relay included in said line circuit at said station; a stick relayat said station having a stick circuit energized through front contactsof said fault and said stick relays, whereby said stick circuit isdeenergized in response to an open condition of said line circuitsufficiently long to drop said fault relay; means independent of saidstick circuit for energizing and picking up said stick relay; andcircuit means requiring that said stick relay be in its picked upposition for permitting the clearing of said signals.

3. In combination, a control ofiice, a distant field station including asection of railway track and a signal for controlling traffic over saidsection, and a communication system for controlling said signal fromsaid control office comprising; a normally energized line circuitconnecting said office and said field station energized by a source ofcurrent in said ofiice, means in said office for intermittentlydeenergizing and reenergizing said line circuit to impress a codethereon including a plurality of successive deenergizations of the linecircuit, a signal control relay at said field station for when energizedtending to clear said si al, a station relay which is temporarilyenergized in response to a series of deenergizations and reenergizationsof said line circuit characterizing a particular code for selecting thatstation, a circuit for energizing said signal control relay including afront contact of such station relay, a slow acting discriminating relayenergized in response to continuous energization of said line circuitand also energized in response to intermittent energization of said linecircuit to characterize a code but deenergized upon a prolongeddeenergization of said line circuit, a stick relay, a pick-up circuitfor said stick relay including a front contact of said station relay, astick circuit for said stick relay including its own front contact and afront contact of said discriminating relay, and a circuit for clearingsaid signal including front contacts of said stick relay and said signalcontrol relay in series, whereby prolonged opening of said line circuitcauses deenergization of said stick relay and actuation of said signalto its stop condition and whereby reenergization of said discriminatingrelay will not return said signal to its clear condition without thetransmission of a code capable of energizing said station relay.

4. In combination, a control office, a distant field station including asection of railway track and asignal for controlling trafiic over saidsection, and a communication system for controllin said signal from saidcontrol ofiice comprising; a normally energized line circuit connectingsaid office and said field station energized by a source of current insaid office, means in said office for intermittently deenergizing andreenergizing said line circuit with impulses of distinctive polaritiesto impress a code thereon including a plurality of successivedeenergizations of the line circuit, a signal control relay at saidfield station for when energized tending to clear said signal, a stationrelay which is temporarily energized in response to a series ofdeenergizations and reenergizations of said line circuit by polaritiescharacterizing a particular code for selecting that station, a circuit 1for energizing said signal control relay including a front contact ofsuch station relay, a slow acting discriminating relay energized inresponse to continuous energization of said line circuit and alsoenergized in response to intermittent energization of said line circuitby different polarities to characterize a code but deenergized upon aprolonged deenergization of said line circuit, a stick relay, a pick-upcircuit for said stick relay including a front contact of said stationrelay, a stick circuit for said stick relay including its own frontcontact and a front contact of said discriminating relay, and a circuitfor clearing said signal including front contacts of said stick relayand said signal control relay in series, whereby prolonged opening ofsaid line circuit causes deenergization of said stick relay andactuation of said signal to its stop condition and wherebyreenergization of said discriminating relay will not return said signalto its clear condition without the transmission of a code capable ofenergizing said station relay.

5. In combination, a control oflice, an indicator at said office, adistant field station including a section of railway track and a signalfor controlling traific over said section, and a communication systemfor controlling said signal from said control ofiice and said indicatorin accordance with the condition of said line circuit comprising; anormally energized line circuit connecting said oifice and said fieldstation energized by a source of current in said office, means in saidoifice for intermittently deenergizing and reenergizing said linecircuit with impulses of distinctive polarities to impress a codethereon including a plurality of successive deenergizations of the linecircuit, asignal control relay at said field station for when energizedtending to clear said signal, a station relay which is temporarilyenergized in response to a series of deenergizations' andreenergizations of said line circuit by polarities characterizing aparticular code for selecting that station, a circuit for energizingsaid signal control, relay including a front contact of such stationrelay, a slow acting discriminating relay energized in response tocontinuous energization of said line circuit and also energized inresponse to intermittent energization of said line circuit by differentpolarities to characterize a code but deenergized upon a prolongeddeenergization of said line circuit, a 76 stick relay, a pick-up circuitfor said stick relay including a front contact of said station relay, astick circuit for said stick relay including its own front contact and afront contact of said discriminating relay, a circuit for clearing saidsignal including front contacts of said stick relay and said signalcontrol relay in series, and means for causing said indicator todistinctively indicate said intermittent energization and said prolongeddeenergization of said line circuit, whereby prolonged opening of saidline circuit causes deenergization of said stick relay and actuation ofsaid signal to its stop condition and whereby reenergization of saiddiscriminating relay will not return said signal to its clear conditionwithout the transmission of a code capable of energizing said stationrelay.

WILLIAM D. HAILES.

